Chronic psychoses

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    Last updated: July 2022


    Chronic psychoses (schizophrenia, paranoid psychosis, etc.) are defined by specific clinical characteristics and their long-term nature.
    Schizophrenia is characterized by delusions, disorganized thinking, hallucinations, depersonalisation, loss of motivation, diminished emotional expression, impaired cognition, abnormal behaviour and neglected hygiene. Such patients are often very anxious.


    The goal of treatment is to reduce symptoms and improve social and occupational functioning. It offers real benefits, even if chronic symptoms persist (tendency toward social isolation, possible relapses and periods of increased behavioural problems, etc.).


    Before prescribing antipsychotic medication, consider the possibility of an underlying organic cause (see Acute confusional state (delirium)) and use of substances. Check and record blood pressure, heart rate and weight. 


    Treatment should last at least one year, possibly for life, particularly in patients with schizophrenia. Uncertainty about the possibility of follow-up at one year or beyond is no reason not to treat. However, it is better not to start pharmacological treatment for patients who have no family/social support (e.g. homeless), provided they do not have severe behavioural disorders.


    Only prescribe one antipsychotic at a time. To limit the risk of adverse effects, start treatment at a low dose and gradually increase until the minimum effective dose is reached. In older patients, reduce the dose by half, whichever medication is used. 


    Haloperidol is the first-line antipsychotic. Preferably use oral haloperidol with a view to switching to long-acting haloperidol (haloperidol decanoate) if the patient is likely to need long-term treatment (e.g. patients with schizophrenia).
    haloperidol PO: start with 0.5 mg 2 times daily for 3 days then 1 mg 2 times daily until the end of the first week; increase to 2.5 mg 2 times daily the second week. After 2 weeks, assess if the treatment is well tolerated and effective. If it is not effective, check adherence; if necessary increase to 5 mg 2 times daily (max. 15 mg daily).


    If haloperidol is not available, contraindicated or poorly tolerated, possible alternative are:
    risperidone PO: 1 mg 2 times daily for one week, then 2 mg 2 times daily for one week; if necessary, increase to 3 mg 2 times daily as of the third week (max. 10 mg daily).
    chlorpromazine PO (especially if a sedative effect is required): 
    25 to 50 mg once daily in the evening for one week; if necessary, increase to 50 mg in the morning and 100 mg in the evening for one week; if necessary, 100 mg 3 times daily as of the third week.

    olanzapine PO: 10 mg once daily; if necessary, increase by 5 mg every week (max. 20 mg daily).


    In case of extrapyramidal symptoms, try reducing the dose of antipsychotic or, if the extrapyramidal symptoms are severe, add biperiden PO: 2 mg once daily, increase if necessary up to 2 mg 2 to 3 times daily (if biperiden is not available, use trihexyphenidyl PO at the same dosage). 


    For severe anxiety, it is possible to add a short-course anxiolytic treatment (for a few days to max. 2 to 3 weeks) to the antipsychotic treatment:
    diazepam PO: 2.5 to 5 mg 2 times daily


    For major agitation:

    • If the patient is not under antipsychotic treatment:

    haloperidol PO 5 mg + promethazine PO 25 mg, to be repeated after 60 minutes if necessary. After a further 60 minutes, if necessary administer promethazine IM 50 mg.
    In case of hostile or agressive behaviour, use IM route (same dose), to be repeated after 30 minutes if necessary; after a further 30 minutes, if necessary, administer promethazine IM 50 mg.
    High doses of haloperidol can induce extrapyramidal symptoms, add biperiden if necessary.

    • If the patient is already under antipsychotic treatment:

    diazepam PO or IM: 10 mg to be repeated after 60 minutes if necessary
    Do not combine two antipsychotics.


    For long-term treatment (e.g. patients with schizophrenia) a long-acting antipsychotic drug can be used once the patient has been stabilised on oral treatment. The dosage depends on the oral dose the patient is taking. The switch from oral to a long-acting antipsychotic should be gradual, according to a specific protocol. For information, at the end of the transition period from oral to long-acting antipsychotic, the dose of haloperidol decanoate IM administered every 3 to 4 weeks is approximately: 

    Daily dose
    of haloperidol PO

    Monthly dose of
    haloperidol decanoate IM (a) Citation a. If haloperidol decanoate is not available, fluphenazine IM: 12.5 to 50 mg/injection every 3 to 4 weeks.

    2.5 mg

    25 mg

    5 mg

    50 mg

    10 mg

    100 mg

    15 mg

    150 mg

    For a patient on risperidone PO: gradually decrease the dose of risperidone by slowly introducing haloperidol PO then, once the patient is stabilised, change to haloperidol decanoate every 3 to 4 weeks as above.

    Special situations: pregnant or breast-feeding women

    • In the event of pregnancy in a woman taking antipsychotics: re-evaluate the need to continue the treatment. If treatment is still necessary, administer the minimal effective dose and avoid combination with an anticholinergic (biperiden or trihexphenidyl). Monitor the neonate for extrapyramidal symptoms during the first few days of life.
    • First symptoms of psychosis during pregnancy: start with the lowest dose of haloperidol and only increase slowly if necessary. 
    • Post-partum psychosis: if the woman is breast-feeding, haloperidol should be preferred.
    • Long-acting antipsychotics should not be administered.
    • (a)If haloperidol decanoate is not available, fluphenazine IM: 12.5 to 50 mg/injection every 3 to 4 weeks.